Home » Some of Our Service Calls in Greater Montreal » Repair of a Midea wall-mounted heat pump in Rosemère
Réparation d’une thermopompe murale Midea à Rosemère
Reading time: 4'

Repair of a Midea wall-mounted heat pump in Rosemère

A service call following a sudden system shutdown

At AirGreen , our teams of HVAC repair experts respond quickly throughout the Greater Montreal region, including the North Shore , South Shore , Laval and Montreal , to diagnose and correct any heating and air conditioning system failure.

That day, our technician went to Rosemère , on the North Shore, after a customer reported that their Midea wall-mounted heat pump had suddenly stopped and was no longer responding in either heating or cooling mode. The system, installed on the roof of a house extension, appeared visually intact, but remained completely inactive despite several restart attempts.

Diagnosis: finding an electrical fault on an inverter compressor

Once on site, our technician began with a methodical inspection of the electrical circuit and system components. The Midea heat pump was a typical inverter wall-mounted unit, installed on overhead supports , with the refrigerant lines carefully sheathed and protected.

Here are the key steps of the diagnosis :

  • Check the supply voltage at the outdoor unit input: correct voltage at 240 V.

  • Main fuse and control board continuity test : continuity interrupted, sign of a blown thermal fuse .

  • Compressor start-up current measurement : no response, confirming an electronic fault linked to the inverter module.

  • Visual inspection : no apparent damage to the condenser, but slight oxidation near the wiring passage, possibly linked to moisture infiltration.

The verdict: the inverter compressor's power board had suffered a power surge, causing the internal fuse to fail and preventing it from starting.

Intervention: replacement of the electronic module and return to service

Our AirGreen technicians are trained and authorized to work on Midea systems, allowing us to repair original electronic components without having to unnecessarily replace the entire unit.

Repair steps:

  1. Disconnect the power supply and secure the work area.

  2. Opening the service panel to access the power board (inverter PCB).

  3. Disassembly of the defective electronic module after complete inspection of the connections.

  4. Installation of a new original Midea compatible module , with verification of the wiring and the probe connector.

  5. Cleaning and dielectric treatment of electrical contacts to prevent moisture.

  6. Power up and complete functional test in heating and cooling modes.

Once the repair was completed, the system restarted immediately. Measurements taken from the manifold and the current clamp confirmed the return to normal operation :

  • Stable intensity at 5.8 A in cold mode.

  • Discharge pressure conforms to 250 psi.

  • Indoor blowing temperature at 11°C.

The customer, who was worried about having to replace his entire unit, was relieved to learn that the fault was repairable at reasonable cost .

Results: reliability and surge prevention

After the system was restored to service, our technician offered the customer a preventative solution : installing a surge protector specifically designed for inverter HVAC systems. This device protects the circuit board from power fluctuations, which are very common during thunderstorms or household power spikes.

We also have:

  • Reorganized and secured the wiring around the wall passage to avoid any moisture points.

  • Added additional insulation sheathing on refrigeration lines exposed to the sun.

  • Recommended a complete annual maintenance , including checking the pressures, the control board and the condensate drain.

AirGreen expertise: rigor and precision in the service of comfort

Every AirGreen intervention is carried out according to Midea manufacturer standards and HVAC best practices . Our team doesn't just replace parts: we analyze the exact cause of the problem to ensure a lasting repair and avoid any recurrence.

This case of electronic failure on a Midea heat pump demonstrates the importance of careful diagnosis and specialized expertise. A misinterpretation could have led to an unnecessary complete replacement, while a simple, properly replaced electronic module was enough to restore the system's efficiency.

Conclusion: A fully operational Midea system

Thanks to our team's quick and methodical intervention, the Midea wall-mounted heat pump in Rosemère has returned to optimal performance. Fresh air is once again circulating efficiently, the operating noise is stable, and the customer now benefits from a reliable, protected, and energy-efficient system .

At AirGreen , we combine technical expertise, rapid response and compliance with HVAC standards to guarantee lasting comfort for every home in Montreal, Laval, Longueuil, the North Shore and the South Shore.

AirGreen — Certified specialists in the repair, maintenance and installation of Midea heat pumps and other leading brands across Greater Montreal.